shukr-sabr-sadaqah asked: Salaams, could you link me to a post about why you feel it is okay to curse the sahaba? Thanks :)
Probably, but the tumblr search function sucks.
Here’s a few narrations or quotes from scholars in lieu of that (I’m mostly cutting and pasting from my book here):
It is narrated that Imām al-Ṣādiq (peace be upon him) used to curse four men and four women after every obligatory prayer, by name: Abū Bakr, ʿUmar, ʿUthmān, Muʿawiyāh, and ʿAyeshah, Hafṣah, Hind and Umm al-Ḥakam, the sister of Muʿawiyāh. [Al-Kafi, v. 3, H5096; This narration is widely regarded as sahih.]
ʿAllammāh Muḥammad Bāqir Majlisī wrote: It is impossible for a sane person to doubt the kufr of ʿUmar, so laʿnat (the curse) of Allāh and His Messenger be upon him, and upon anyone who considers him a Muslim, and upon anyone who restrains from doing laʿnat on him. [Jilā’ al-ʿUyūn, p. 45.]
Shaykh al-Kashi reported from Dāwūd ibn al-Nu’man who said: Al-Kumayt entered upon ʿAbdullāh (peace be upon him) and implored: O my master! I want to ask you regarding an issue. Imām said: Ask. Al-Kumayt said: I want to ask regarding Abū Bakr and ʿUmar. So Imām said: O Kumayt ibn Zaid! A drop of blood does not spill, wealth is not obtained in ḥarām manner and neither does fornication happen but that it (the sin) is on their necks until our Mahdi rises. And we community of Banī Hāshim order our older ones and younger ones to insult (or, abuse) them and do tabarrā from them. [Rijāl al-Kashī, v. 2, p. 464.]
Muhammad ibn al-Hasan al-Hur, as part of a longer narration, said: I was with Amirul Mu’minin doing tawwaf around the Ka`bah. He (peace be upon him) saw a man clinging to the curtain of the Ka`bah and he was saying salawat on Muhammad and Aale Muhammad, and he (Amirul Mu’minin) said salam to him. We passed him a second time (and now the man was doing la`nat on the enemies of Aale Muhammad), but he (peace be upon him) did not say salam to him this time. I asked: O Amirul Mu’minin, why didn’t you say salam to him this time? He (peace be upon him) said: Because I did not want to interrupt his la`nat (since by saying salam, he would be obliged to stop and return my salams), as la`nat (on our enemies) is better than giving and returning salam, and more excellent than saying salawat on Muhammad and Aale Muhammad. [Majmu`a al-Nurayn, p. 208]
The Messenger of Allah (may Allah bless him and his pure family) said: When, after me, you find the People of Doubt and Innovation (e.g., the shaykhayn, their lovers, and supporters), do bara’at from them, and maximize your insulting (abuse) of them, and utterly denounce them (in the strongest possible terms), and drive a wedge, so that they may not become greedy for the corruption of Islam. You must warn people against them and against learning their heretical innovations! Allah will reward you for this and will raise your position in the hereafter. [Al-Kafi, v. 2, H2814; This narration has been been declared sahih or, at a minimum, reliable, by a number of scholars, including `Allamah Majlisi, Ayatollah al-Khoei, Shaykh Tabrizi, etc.]
Zurarah (may Allah grant him mercy) reported that Imam al-Sadiq explained the verse {Whosoever brings a good deed shall have ten times the like thereof to his credit}: Whoever mentions Abu Bakr and `Umar, then sends la`nat (curses) on them every morning, Allah will write for him seventy hasanat, and remove from him ten bad deeds, and raise his rank by ten positions. [Tafsir al-`Ayyashi, v. 1, p. 387; Mukhtasar al-Basa’ir, p. 35.]
The Holy Prophet (peace and blessings be upon him and his pure family) said: May the curse of Allah, the angels, and all mankind, be upon whoever chooses an imam other than his True Imam, or chooses a mawla other than his True Mawla. [`Uyun al-Akhbar al-Rida, v. 2, Ch. 31, h271.]
Hanan said: I once asked Imām al-Bāqir (peace be upon him) about the children of Yaʿqub (peace be upon him), that is, if they were prophets. He (the Imām) said: No, they were not prophets but rather they were the grandsons of the children of prophets, who did not pass away without repentance and remembering what they had done. And the Shaykhayn (Abū Bakr and ʿUmar) passed away without repenting or remembering what they had done to Amīrul Mu’minīn ʿAlī (peace be upon him). May the curse of Allāh, the angels and all the people be upon them. [Al-Kāfī, v. 8, H14791.]
The Messenger of Allāh (may Allāh bless him and his pure family) said: Those who want Allāh to bestow on them everything that is good should follow ʿAlī after me, love his friends, and be the enemy of his enemies. [Bishārāt al-Muṣṭafā, p. 220, H15; Amālī al-Ṣadūq, p. 382.]
The Prophet (may Allāh bless him and his pure family), as part of a longer narration, said: Fāṭimah will say to Allāh: O Lord! I am weary of this life and tired of the people of this world. So take me to my father. So Allāh will join her with me and she will be the first one from my family who joins me. She will come to me grieved, depressed, harmed, extorted, and murdered. Then I will say to Allāh: O Allāh! Curse those who were unjust to her, torment those who constrained her, and humiliate those who humiliated her. And make the one who kept kicking her ribs, until he killed her fetus, dwell in Hell. And the angels will say: Ameen. [Irshad al-Qulub al-Daylami, v. 2, p. 295; Bishārāt al-Muṣṭafā, p. 307, H6; Amālī al-Ṭūsī, v. 1, p. 100.]
And there are literally dozens and dozens more narrations and quotations from our scholars just like this. Insha’Allah, though, this small sampling will be of some use to you.
There are some indisputable Qur’anic evidences for this too, but it’s a bit much to go into at this point (although it would make a good post for later, insha’Allah).